Ammunition cartridge



June 23, 1970 G. E. HENDRICKS AMMUNITION CARTRIDGE Filed Jan. 25. 19

INVEN'IOR. GROVE/P E. HE/VDR/CKS A 7' TO/QNE) United States Patent US.Cl. 102-45 2 Claims ABSTRACT OF THE DISCLOSURE An ammunition cartridge,including a cartridge casing having a base, a projectile and a powdercharge contained within the casing. A primer is positioned within thebase of the casing and includes an anvil, primer cover, and a preformedprimer powder unit. The anvil includes a substantially cylindrical coreand an integral concentric cylindrical wall spaced from the core todefine a longitudinal annular groove. The anvil core has a longitudinalbore therein. The primer cover has an end wall and a substantiallycylindrical wall. The preformed primer unit includes a thin walledenvelope confining a powder charge and is positioned within the primercover adjacent the end wall thereof. The primer cover encircles part ofthe anvil core and is seated within the annular groove in the anvil withits end wall spaced from the anvil.

BACKGROUND OF THE INVENTION This invention relates to ammunitioncartridges.

Primers heretofore used in ammunition cartridges were assembled with theprimer powder being inserted into the primer cup or the cartridge casingin an inert or muddy state. After final assembly of the cartridge, theprimer was baked for a predetermined period of time and at apredetermined temperature so as to transform its powder into anexplosive mixture. The firing hole at the forward end of the primer wasthen sealed by a lacquer or paper sealing material to prevent the primerpowder from being contaminated or subjected to moisture.

SUMMARY OF THE INVENTION This invention relates to an improvedammunition cartridge in which the primer charge is enclosed in a thinwalled envelope with said envelope being positioned within the base ofthe cartridge casing so that the primer powder charge is susceptible todetonation by a percussive force directed toward the casing base.

In this invention the primer powder charge is formed into aprefabricated sealed wafer which is inserted into the circumferentialmargin of the base of a rimfire ammunition cartridge or into the primerassembly of a centerfire ammunition cartridge and which needs noapplication of heat after insertion to render it usable. The primercharge, by being sealed in a thin walled envelope, is substantially freeof contamination and moisture, thus eliminating the need for sealing thefire hole of the primer assembly. In addition, the prefabricated primerwafer may be readily handled, thereby permitting the primer assembly tobe assembled easily.

Accordingly, it is an object of this invention to provide an ammunitioncartridge that can be readily and eco nomically assembled.

It is a further object of this invention to provide an ammunitioncartridge which can be safely handled by the user and which may bereliably detonated by the hammer or firing pin force of a firearm.

It is a further object of this invention to provide an ammunitioncartridge of economical and simplified construction.

Other objects of this invention will become apparent upon a reading ofthe inventions description.

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BRIEF DESCRIPTION OF THE DRAWINGS The preferred embodiments of theinvention have been chosen for the purposes of illustration anddescription wherein:

FIG. 1 is a longitudinal sectional view of a rimfire ammunitioncartridge.

FIG. 2 is a side elevation of the primer utilized in the ammunitioncartridge of FIG. 1, with part broken away.

FIG. 3 is a longitudinal sectional view of a centerfire ammunitioncartridge.

FIG. 4 is a cross sectional view of the prefabricated primer waferutilized in the primer assembly of the ammunition cartridge of FIG. 3.

FIG. 5 is a side elevation of the prefabricated primer wafer utilized inthe primer assembly of the ammunition cartridge of FIG. 3.

FIG. 6 is a longitudinal sectional view of a primer assembly utilized inthe centerfire ammunition cartridge of this invention.

FIG. 7 is a longitudinal sectional view of a modifica tion of the primerassembly of FIG. 6.

FIG. 8 is a right end view of the primer assembly of FIG. 7.

FIG. 9 is a longitudinal sectional view of another embodiment of aprimer assembly used in the centerfire ammunition of this invention.

FIG. 10 is a longitudinal sectional view of a modifica tion of theprimer assembly of FIG. 9.

FIG. 11 is a longitudinal sectional view of another modification of theprimer assembly of FIG. 9.

FIG. 12 is a longitudinal sectional view of another embodiment of acenterfire ammunition cartridge.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The preferred embodimentsillustrated are not intended to be exhausted or to limit the inventionto the precise forms disclosed. They are chosen and described in orderto best explain the principles of the invention and its application andpractical use to thereby enable others skilled in the art to bestutilize the invention.

This invention pertains to ammunition cartridges of which two generaltypes are illustrated by FIGS. 1 and 3.

FIG. 1 illustrates a rimfire ammunition cartridge which comprises acartridge shell 22 having an annular base flange 24, a primer 11, apowder charge 26 and a projectile head 28. The powder 12 of primer 11may be of the type commonly used in toy cap guns and is arranged in abody of annular or ring shape as shown in FIG. 2 and enclosed in anenvelope 14. Envelope 14 is preferably formed from thin sheets of paperor other breakable and combustible material having suffirient rigidityto retain its wafer-like shape after being inserted into a cartridge. Toretain the powder 12 in its annular shape and to prevent its leakage andcontamination, envelope 14 is preferably sealed about the outer andinner circumferential peripheries of the powder ring 12 and sized toclosely conform to the peripheries of the powder ring thereby formingthin circumferential margins 16 and 18.

Primer 11 is inserted into cartridge shell 22 to abut base 13, withouter margin 16 and preferably a portion of the powder 12 fitting intoan interior annular groove 25 formed between base flange 24 andcylindrical wall 27 of shell 22. The powder charge 26 is then placed inthe cartridge shell 22 adjacent to or in contact with the primer 11 andthere confined by projectile head 28 whose inner part fits in the openend part of the cartridge shell 22 and is preferably fixedly mountedtherein by a crimp 23.

FIG. 3 illustrates a centerfire ammunition cartridge which comprises acartridge casing 2, primer assembly 4, wad and shot carrier 6,projectile powder charge 8 and shot charge 9. Primer assembly 4 ismounted in a concentric aperture 7 in the base of cartridge casing 2and, although illustrated in FIG. 3 as the primer assembly shown indetail in FIG. 10, can assume any of the various primer assemblyembodiments illustrated by FIGS. 6, 7, 9, 10 and 11.

The primer powder 30 used in each of the primer assemblies illustratedin FIGS. 6, 7, 9, 10 and 11 may be of the type commonly used in toy capguns and is mounded as shown in FIGS. 4 and 5 and enclosed in anenvelope 29 so as to form a primer wafer 10. Envelope 29 is preferablyformed from thin sheets of paper or other breakable and consumablematerial having suflicient rigidity to retain its wafer-like shape afterbeing inserted into the primer assembly. To retain the powder 30 in itsmounded shape and to prevent its leakage and contamination, envelope 29is preferably sealed about the outer circumferential periphery of thepowder mound and is generally sized to conform to the outer powder moundperiphery so as to form an annular margin 32.

The primer assembly of FIG. 6 includes a deep walled battery cup 34having an aperture 36 preferably concentrically located in its base anda flanged rim 35. A cylindrical anvil 38 with an axial bore 40therethrough is press fit into battery cap 34. Anvil 38 iscircumferentially shouldered to provide a seat for the edge of acupshaped primer cover 42. The primer wafer 10 is inserted into primercover 42 and positioned against its base 43. Wafer 10 may be heldagainst base 43 by an adhesive or may have a diameter equal to orgreater than the inner diameter of the primer cover so that it may havea press fit at its periphery within the primer cover 42. The primercover 42 with wafer 10 positioned therein is mounted over anvil 38 andpress fit into the battery cup 34 with the edge of cover 42 restingagainst shoulder 44 of the anvil 38. The depth of primer cover 42 andthe longitudinal location of shoulder 44 to anvil 38 is such that, withthe edge of the primer cover seating against shoulder 44, the primerwafer 10 lightly contacts anvil 38 with the mounded powder 30 partiallyoverlying bore 40.

A modification of the primer assembly of FIG. 6 is shown in FIG. 7 inwhich the anvil 46 is in the form of a plate. Anvil plate 46 preferablyhas a thickness which is less than the diameter of aperture 36 andcontains a notch 37 in its end which is positioned adjacent aperture 36.

The primer assembly of FIG. 9 includes a deep walled cup shaped primercover 50. A primer wafer 10 is inserted into the primer cover 50 andpositioned against its base 51. The wafer 10 is held against the base 51by any one of the means hereinbefore described. A cylindrical anvil 52having a shouldered portion 14 is press fit into the primer cover 50with the shoulder portion 54 seating upon the edge 56 of primer cover50. Anvil 52 has an axial bore 58 therein which may be sealed at itsexposed end by thin membrane 60. Membrane 60 is preferably formed as anintegral portion of anvil 52 and will rupture at time of firing. Thedepth of primer cover 50 and the longitudinal location of anvil shoulderportion 54 are such that, with the edge of the primer cover seatingagainst the anvil shoulder portion, the primer wafer 10 is slightlyspaced from anvil 52 with the mounded powder partially overlying bore58.

A modification of the primer assembly of FIG. 9 is shown in FIG. 10 inwhich primer cover 50 has an exterior flange 64 formed about its base.

Another modification of the primer assembly of FIG. 9 is shown in FIG.11 in which anvil 90 is of a cylindrical configuration having axial bore92 therein. Anvil 90 includes a core portion 93 and a spaced concentricintegral anular wall 96 defining a narrow deep annular groove 94. Snuglyseated within annular groove 94 is a cylindrical wall 97 of cup-shapedprimer cover 98. A

primer wafer 10 positioned in cover 98 bears against its base. Therespective depths of primer cover 98 and annular groove 94 are suchthat, with the edge of the primer cover wall 98 seated against thebottom of the annular groove 94, the primer Wafer 10 is slightly spacedfrom anvil with its mounded powder 30 partially overlying bore 92. Theend portion of anvil side wall 96 may terminate in an outwardlyprojecting annular flat flange which is preferably flush with the baseof the primer cover 98 or which may extend slightly beyond the base ofprimer cover 98. Anvil bore 92 may be sealed at its exposed end by thinmembrane 102 which preferably constitutes an integral part of anvil 90and which will rupture at time of firing.

The anvils utilized in the aforedescribed cartridges may be of eithermetal or hard plastic. The advantage of using a plastic anvil is that itpermits the use of thinner material for the primer cover since theplastic will slightly deform under the hammer action of the firing pinrather than provide an unyielding part which could perforate the cover.

The slight space or air gap between the primer wafer and the anvil ofthe primer assembly is an optional modification. The advantage of suchan air gap is that it provides a margin of safety against detonation ofthe primer powder during assembly of the primer and subsequent handlingby the ammunition cartridge user. Of course the air gap, whenincorporated, is very slight and will not prevent the primer powder fromforceably contacting the anvil upon deformation or movement of theprimer cover under the force exerted by the firing pin of a gun. Alsothe membrane sealing the anvil bore or firing part is optional. Itspresence or absence depends in part upon the desirability of sealing theanvil bore to the cartridge powder charge, and where used it will bereadily ruptured upon firing.

A primer assembly of similar configuration to that illustrated in FIG. 9may be sized to fit within the end portion of a cylindrical ammunitioncartridge as shown in FIG. 12. This primer assembly comprises an anvil70, a cup-shaped primer cover 76 and a primer wafer 10 and is press fitinto the end portion of shell casing 78. The outer surface 79 of anoutturned annular casing flange 80 formed on casing 78 is preferablyflush with the exposed surface of base 91 of the primer cover 76. Theanvil 70 has an axial bore 72 which preferably flares at its inner endto form a portion of the powder charge chamber 73. Primer wafer 10lightly touches anvil 70 overlying and preferably sealing the end ofbore 72. Confined within chamber 73 by a wadding 82 is a powder charge74. Shot members 84 are contained in the casing 78 outwardly of wadding82 and are confined within shell casing 78 by an end wall 86 formed byinwardly bending and crimping the end portion of casing 78.

What I claim is:

1. In an ammunition cartridge including a cartridge casing having abase, a projectile and a powder charge contained within said casing, aprimer positioned within the base of said casing and includng an anvil,primer cover, and a preformed primer powder unit, said anvil having asubstantially cylindrical core and an integral concentric cylindricalwall spaced from said core to define a longitudinal annular groove, saidcore having a longitudinal bore therein, said primer cover having an endwall and a substantially cylindrical wall, said preformed primer unitincluding a thin-walled envelope confining a primer powder charge, saidpreformed primer unit being positioned within said primer cover adjacentits end wall, said primer cover encircling a part of said anvil core andseated within said angular groove and having its end wall spaced fromsaid anvil to confine said preformed powder unit with its powder chargesubstantially aligned with said anvil core bore and detonatable uponapplication of percussive force to said primer cover.

2. The ammunition cartridge of claim 1, wherein said upon firing.

Re 4,076 Re 7,394

anvil includes an integral membrane which encloses one end of saidlongitudinal bore and which is rupturable References Cited UNITED STATESPATENTS Moffatt 102-45 Hotchkiss 102-45 Van Vechten 102-45 Mills 102-38X Quinlan et a1 10243 10 6 3,195,463 7/1965 Foote et al. 102-86.53,236,181 2/1966 Woodring et a1. 102-45 3,352,240 11/1967 Eckstein102-45 FOREIGN PATENTS 1,429,346 l/1966 France.

BENJAMIN A. BORCHELT, Primary Examiner S. C. BENTLEY, Assistant Examiner

